Febdeeick m



(No Model.) 2 -SheetsSheef 1.

L. WILKINSON, De0d., F. M. mm, administrator.

v SGREW GUTTING MACHINE. N0. 322,85. Patented July 21, 1885.

E U ZT Wff/mssesx WM NITED STATES PATENT OFFICE.

LEWIS WILKINSON, OF CHICAGO, ILLINOIS; FREDERICK M. STEEL, ADMINISTRATOR OF SAID YWILKINSON, DECEASED.

SCREW-CUTTING MACHINE.

SPECIFICATION forming part of Letters Patent No. 322,875, dated July 21,1885.

Application filed June 5, 1884. (No model.)

To all whom it may concern:

Be it known that I, LEwIs WILKINSON, a citizen of the United States,residing at Ohicago, in the county of Cook and State of Illinois,haveinvented certain new and useful improvements in Screw-Cutting Machinesof which the following is a specification, to wit:

This invention relates to machines for threading bolts and screws; andit consists in certain peculiarities of the construction and arrangementof the same, substantially as will be hereinafter more fully set forthand claimed.

In order to enable others skilled inthe art to which my inventionappertains to make and use the same, I will now proceed to describe itsconstruction and operation, referring to the accompanying drawings inwhich,--

Figure 1 is a perspective view of a machine embodying my improvements.Fig. 2 is a top view of the cutting-head; Fig. 3, a similar view, withthe cap removed, showing the dies and their action. Fig. 4 is a sideelevation of the cutting-head; Fig. 5,a cross-section of the same online x m, Fig. 3. Fig. 6is a perspective view of one of thecutting-arms; Fig. 7, a detail of my reversible die; and Fig. 8 is adetail view of the bolt or screw holder and its clutch.

A represents the main frame of a screw and bolt cutting machine, havinga vertical driving-shaft, A, journaled in suitable boxes thereon, andarranged to slide therein a suitable distance to properly feed the screwor bolt to the stationary cutting-head below, which carries the dies, aswill be presently described. This shaft is provided with fast and loosepulleys a a, driven bya belt, aZfrom any desired power, and belowthesepulleys the shaft'is provided with a collar, 1), with which engages ashifting-arm, B, which extends downward and is jointed to a foot-lever,

,B, fulcrumed in the lower part of the main frame. This foot-lever isprovided with a shifting weight, B which is adjusted upon the lever tonearly balance the weight of the driving-shaft and its attachments, andserves the double purposeof aiding the pressure of the foot in liftingthis shaft and controlling the downward pressure which it exerts uponthe bolt or screw in feeding it to the dies. The

lower end of the driving-shaft is madehollow, and its end is formed witha clutch or ratchet face, b, which engages with a similar face, b uponthe upper side of the driving-head B, the shank of which extends withinthe hollow driving-shaft, and has its upper end formed with a broadcircumferential groove, b which engages the end of a screw, b, in theshaft,aud prevents the head from dropping out of the shaft, whileallowing it sufficient play to release it from the clutch and allow itto stop running as soon as the thread is formed upon the bolt or screwunder operation.

The main frame is also provided with a shallow pan or receptacle, 0,divided by a partition, 0, into two compartments, the outer of whichserves to hold the work to be operated upon, and the inner, beneath thedriving-shaft, is wholly or partially filled with oil, as indicated inFig. 1. Upon one or more short standards, d, in this oil-pan issupported a stationary cutting-head, having dies inclosed therein. Thecutting-head is composed of a circular plate, D, having a flange, d,around its lower edge, and formed with a series of radial grooves inwhich are placed the die-carrying arms or holders D. These are on theirfor- 'ward ends formed with aslot, d, in which is placed the steel die Dconsisting of a steelplate formed with four equal sides, two or more ofwhich are provided with cutting-teeth d as shown in the drawings, Figs.6 and 7.

These dies are pivoted in the slotted arms by a pin or screw, d passingthrough their center, and are formed with a series (preferably four) ofholes dflthrough one of which passes a pin, 01 These dies v may beremoved and replaced at any time, and when one face is dull the pin d isremoved, the die turned upon its pivot to present a new workingrface,and the pin again replaced, the holes (1 in the die being all formedequidistant from its center, and therefore all corresponding to theposition of the locking-pin, as will be evident; Thedie may have two orall of its faces formed with cutting-teeth, and, if desired, these maybe of various sizes suitable for cutting different threads.

The rear ends of the die-holding arms D are formed or provided withhook-shaped lugs d which engage cam-grooves e in a ring,

E, surrounding the main body of the head D, and resting'upon itsflanges; and it is evident that the turning of this ring will withdrawor advance the dies to release or engage the bolt or screw underoperation. Around the camring E is a second ring, E,fitting closelythereon. This ring is held in proper adjustment upon the ring E by meansof a set-screw, e, and is provided upon its outer side with a cam-plateor incline, 6 A spring, E connects the outer ring with the main frame ofthe machine, and throws the dies back, while they are automaticallythrown forward by a cord or wire, 6 attached to the adj ustingring andrunning over a small pulley, a on the frame, and attached to theshifting-rod B, as in Fig.

Upon the standard 01, below the cuttinghead, is a sliding arm, G, theinner end of which carries a screw-threaded pin, enter-- ing the centerof the plate D between the ends of the dies, and the outer end of whichcarries a stop-pin, g, passing up through the flange d, and engaging theincline e on the ring E. The sliding arm is held up by a spring, G, uponthe standard, as shown.

The operation is as follows: The foot-lever is pressed down,thus liftingthe driving-shaft, and at the same time,by means of the cord 0 turningthe rings E E to throw the dies into their proper place, the incline epassing over the pin 9, the pin springing up again behind the inclineand holding the dies in position. The bolt or screw to be cut is thenplaced with its head in the recessed lower end of the driving-head, andthe shaft A allowed to fall. This engages the clutches b b and the boltis rapidly revolved. It is entered in the cutting head and is threadedby the dies, being pressed down by the weight of the drivingshaft withmore or less rapidity, as regulated by the adjustment of the weight uponthe foot-lever. When the thread is nearly cut, the end of the boltengages and presses down before it the pin 9 and arm G, which at theproper time releases the incline e and allows the spring E to throw thecam-ring around, at once drawing back the dies and releasing the bolt,the weight of which causes the driving-head to drop a short distance,andreleases the clutch. The shaft A is again lifted, the dies returned toplace, and the bolt or screw removed and another substituted. The actionof all the parts is thus made automatic, and it will be seen that theadjusting of the ring E upon the cam-ring within it will cause the diesto be advanced a greater or less distance and fit different sizes ofscrews. The dies being held stationary within the oil-pan are alwayslubricated thoroughly, while none of the oil is thrown off and lost bycentrifugal motion, as is the case when the dies are revolved. Then,too,the cuttings fall freely through the die-head, and do not obstructthe work or clog the machine, while the dies are prevented from injuryby being'at once retracted when the thread is cut of the desired len'th.

It will be observed that the collar 1) upon the driving-shaft acts as astop to prevent the shaft from dropping too far, and when the bolt haspressed down the trigger and released the dies the stop on thedriving-shaft engages the main frame, while the incline 6 furtherdepresses the stop and allows the bolt and its holder to drop of theirown weight and release it from the clutch. This allows the bolt to stoprevolving and prevents it from injuring the dies. The incline does notpass entirely off the stop-pin, and is therefore readily drawn backagain, as will be evident.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

.1. In a screw-cutting machine, the combination, with a revolvingblank-holder sliding Vertically in the main frame, of a cuttingheadprovided with dies sliding radially to and from the center, and aspring-actuated cam for operating them, and a spring arm or triggerengaging the cam during the cutting, but operated automatically by thescrew under operation to release the cam when the cuttingis finished,substantially as shown and described.

2. In a screw-cutting machine, a stationary die-plate, having diessliding in radial grooves therein, and a spring-actuated stop pin ortrigger upon its outer side, in combination with a ring surrounding theplate and formed with cam or eccentric grooves with which the diesengage, and a second ring surrounding the first, and adjustable thereonby means of a set-screw, and provided with a projection for engaging thestop-pin to hold the dies in place, and a spring secured to the outerring to move it when released, substantially as and for the purpose setforth.

3. In a die-holder for screw-cutting, the combination,with thedie-holding arm,formed with a slot in its forward end, of a die-platehaving a series of equal-toothed cutting-edges, pivoted in the slottedholder, and having means, substantially as shown and described, forsecuring it with either of its cutting-edges presented for work,substantially as and for the purpose set forth.

4. In a screw-cutting machine, a drivingshaft having its lower endformed hollow, and having a clutch-face, and a b12tIlk-h0ld61' alsohaving a clutch-face, and a shank sliding endwise a short distancewithin the hollow shaft,in combination with a series of radiallymovingdies, and means, substantially as herein described, for withdrawing thedies and allowing the bolt to fall as soon as the thread is cut, wherebythe bolt is not liable to injure the dies, substantially as shown and described.

5. In a screw-cutting machine, the driving IIO 10 justing-ring E, springE incline c and stoparm G, having pins 9 9', all constructed andarranged to operate substantially as and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

LEWIS WILKINSON.

Witnesses:

W. O. MOARTHUR, CHAS. KRESSMANN.

